2 router config advice please

I was planning to upgrade my home network to 11g from 11b (finally). I currently have 3 PCs on the network -- 1 wired, 2 wireless. I also have a Tivo Series 2 on the network, used for photo, music and video sharing with a PC, whose USB adapter would be upgraded as well. From reading posts in the forum, I've come to the conclusion that I'd be better off connecting the Tivo to a second router via the LAN port and bridging to my primary router. Sounds fine. If so, both routers would be new (i.e. won't keep the 11b router). Now the questions:

1. Which of the WRT54xx models would serve this purpose best (assuming that the 54G v.5 is out of the question)?

2. Does the Linksys firmware natively support bridging or some other functionality that would serve this purpose? Or should I be looking at 3rd party firmware instead?

3. If a bridge is set up between 2 WRT54GS, can the Speed Booster functionality be used? If the other adapters on the network are not Speed Booster-enabled (i.e. plain 11g), is there an issue or speed degradation from the mixed environment?